Citronellyl and/or dihydrocitronellyl lactates, their preparation and their use

ABSTRACT

The invention concerns novel chemical compounds, namely citronellyl lactate and dihydrocitronellyl lactate and their optically active forms. The invention also concerns the method for obtaining them. The invention further concerns their use in the field of perfumes.

This application is an application under 35 U.S.C. Section 371 ofInternational Application Number PCT/FR99/01181 filed on May 18, 1999.

A subject of the present invention is new chemical compounds, namelycitronellyl lactate and dihydrocitronellyl lactate and their opticallyactive forms.

The invention also relates to a process for obtaining them.

The present invention relates in particular to their use in the field ofperfumery. The said compounds have interesting olfactory properties andcan be used, inter alia, for the preparation of perfuming compositionsand perfumed products.

The perfumery industry is constantly seeking products which, through theoriginality, volume and power of their fragrance, confer a quite specialcharacter upon the compositions in which they feature.

The literature contains very little information about the use of lacticesters in perfumery.

It has now been found that citronellyl lactate and dihydrocitronellyllactate and their optically active forms defined below displayedoriginal olfactory properties.

It is to be noted that it is impossible for a person skilled. in the artto foresee whether a given chemical compound will or will not possess asmell that is interesting from the olfactory point of view and what itscharacter will be.

A subject of the invention is thus new esters of lactic acid,citronellyl lactate and dihydrocitronellyl lactate conformingrespectively to formulae (I) and (I′):

The invention also relates to the optically active (R) and (S) formsconforming to formula (Ia) and (I′a):

In the formulae (Ia) and (I′a), the optically active carbon atom takeninto consideration is the carbon atom in a position of the CH₃ group andof the ester function.

It has been found that, depending on the form of the said lactates, thatis to say according to whether they were in racemic form or in a pureoptically active form, they presented a different smell.

Thus, the (R)-citronellyl lactate exhales a flowery character of lily ofthe valley type, warm and rich and more natural than rosy alcohols,whereas the (S)-citronellyl lactate displays a flowery honeysucklecharacter closer to citronellol, which gives it a less natural effectthan the (R)-citronellyl lactate.

As regards the racemic mixture, the smell of the citronellyl lactate hasa flowery character of lily of the valley/honeysuckle type which is lesspowerful and less natural than the (R)-citronellyl lactate.

As far as the (R)-dihydrocitronellyl lactate is concerned, it has acitronella-like, grassy, woody character, whereas that of the(S)-dihydrocitronellyl lactate is of the rosy, woody and lemony type.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a NMR¹H spectrum of(R)-dihydrocitronellyl lactate.

FIG. 2 is a NMR¹H spectrum of(S)-dihydrocitronellyl lactate.

The compounds of formula (I) and (I′) and their optically active forms(Ia) and (I′a) can be prepared by different preparation methods.

One of the access routes to the compounds of formula (I) and/or (I′)comprises the reacting of:

lactic acid, its salts or esters of formula (II):

 in formula (II), R′ represents a hydrogen atom, an alkali-metal atom,an ammonium radical or an alkyl radical, linear or branched having from1 to 4 carbon atoms,

and the citronellol of formula (III) and/or the dihydrocitronellol offormula (III′):

As regards the preparation of the optically active compounds conformingto formula (Ia) and (I′a), they can be obtained by the reacting of:

lactic acid, its optically active salts or esters of formula (IIa):

 in formula (IIa), R′ represents a hydrogen atom, an alkali-metal atom,an ammonium radical or an alkyl radical, linear or branched having from1 to 4 carbon atoms,

and the citronellol of formula (III) and/or the dihydrocitronellol offormula (III′):

According to the process of the invention, the lactic acid or itsderivatives are reacted with the citronellol or the dihydrocitronellol.

As regards the compounds of formula (II) or (IIa), use is made moreparticularly of lactic acid, sodium or potassium lactate, or of themethyl or ethyl esters of lactic acid.

To prepare an optically active lactic ester (Ia) or (I′a), the startingpoint is the optical isomer of formula (IIa) having the desired (R) or(S) configuration, in the knowledge that the reaction allows thepreservation of the stereochemistry of the original isomer.

The (R)-lactic acid or its derivatives are used for preference.

A compound of formula (IIa) having a good optical purity, generally lessthan 10% of the other enantiomer, preferably less than 5%, and even morepreferably less than 3%, even down to 0%, is chosen for preference.

Compounds of formula (IIa) meeting the aforementioned requirements arefound in the trade.

Thus, the commercial lactic acid which is generally found in the form ofa 85% aqueous solution can be used.

As regards the alcohol, an alcohol is used which has a good chemicalpurity preferably exceeding 85%.

Depending on the form of the compound of formula (I), (I′) or (Ia),(I′a), several modes of preparation can be considered.

A first reaction comprises the reacting of the lactic acid with thecitronellol and/or the dihydrocitronellol. It is also possible to carryout the esterification in the presence of an organic solvent. Theorganic solvent is chosen in such a way that it forms an azeotrope withthe water and the boiling point of its azeotrope with the water is lowerthan that of the alcohol involved. Examples of solvents that can becited in particular are toluene, cumene or pseudocumene.

A second variant is to react the lactic acid or its salts in anactivated and protected form with the citronellol and/or thedihydrocitronellol. Thus, the lactic acid or its salts are first reactedwith phosgene, diphosgene (trichloromethylchloroformate) or thionylchloride in order to obtain, respectively, dioxolan-1,3dione-2,4-methyl-5 or propene-one-1 sulphite-1,2 with which thecitronellol and/or the dihydrocitronellol is reacted. The quantity ofphosgene, of diphosgene or of thionyl chloride used is generally equalto the stoichiometric quantity.

A third variant is to carry out the reaction of the lactic acid in esterform with the citronellol and/or the dihydrocitronellol, then distill ofthe corresponding alcohol liberated by transesterification.

The different reactions are carried out in the presence of a standardacid-type catalyst. There may be cited in particular sulphuric acid,sulphonic p-toluene acid, antimony oxide, alkyl or aryl titanates suchas the titanates of methyl, ethyl, n-propyl, isopropyl, t-butyl,cyclohexyl, phenyl, tolyl; monoethanolamine titanate, diethanolaminetitanate, triethanolamine titanate.

Sodium methylate or potassium methylate can also be used.

The quantity of the reagents present is determined in such a way thatthe molar ratio between the lactic acid and the citronellol and/or thedihydrocitronellol varies between 0.5 and 5, and preferably between 1and 3.

The quantity of catalyst used, expressed relative to the weight of thelactic acid or derivative, is advantageously chosen between 0.1 and 5%.

When an organic solvent is present, the quantity used can vary greatly.By way of indication, it can be stated that the quantity of organicsolvent can represent from 50 to 200% of the weight of the lactic acidused.

The temperature of the reaction is chosen so that it is sufficient toallow the completion of the reaction and the distillation of theliberated alcohol if necessary.

The temperature of the reaction is preferably chosen between 50 and 150°C.

The reaction is advantageously carried out under reduced pressureadvantageously between 5 and 500 mbar.

The reaction is preferably carried out under atmosphere of an inert gaswhich can be nitrogen or a rare gas, preferably argon.

From a practical point of view, the procedure according to the inventionis simple to implement.

The different reagents can be introduced in any order. For preference,the following order of reagents is chosen: the lactic acid or derivativeis introduced and the citronellol and/or the dihydrocitronellol, thenthe acid catalyst.

The reaction medium is raised to the desired temperature, while keepingthe reaction medium under agitation.

During the reaction, there is formation of water or release of alcoholin the reaction medium. A preferred variant of the invention comprisestheir elimination form the reaction medium, as and when they form, byany known means, in particular by azeotropic distillation.

At the end of the reaction, the desired lactic ester, the citronelloland/or the dihydrocitronellol in excess and the catalyst are obtained.

The lactic ester which has formed can be recovered from the reactionmedium, by any appropriate means.

Thus, in particular, a washing with water can be carried out followed bya neutralization with the help of a base.

The quantity of base, preferably soda, is such that the pH is between 6and 8.

The organic phase is separated and fractionated by distillation.

Most often there is collection first of all of the excess of citronelloland/or the dihydrocitronellol then of the desired lactic ester which canbe, according to the case, a racemic mixture of citronellyl lactate offormula (I) and/or of dihydrocitronellyl lactate of formula (I′) ortheir optically active forms of formula (Ia) or (I′a) or possibly amixture of optically active forms.

Thus, in the following description of the invention, the term “lacticester” takes account of its different variants.

Another subject of the present invention has as its aim perfumingcompositions, products and perfuming substances characterized by thefact that they contain, as active principle having an influence on thesmell, an effective quantity of at least one lactic ester of formula(I), (I′), (Ia) and (I′a).

The esters of the lactic acid and of the citronellol are particularlyinteresting. As previously mentioned, the ester in (R) form exhales aflowery character of lily of the valley type, warm and rich, while the(S) form has a flowery honeysuckle character.

The different products of the invention can serve as a base for thehoneysuckle, lily of the valley and gardenia characters.

The term “perfuming compositions” is used to describe mixtures ofvarious ingredients such as solvents, solid or liquid supports, fixingagents, various odorizing compounds, etc . . . in which at least onelactic ester of the invention is incorporated, which mixtures are usedto endow various types of finished products with the sought fragrance.

The bases for perfume constitute preferred examples of perfumingcompositions in which at least one lactic ester of the invention can beadvantageously used.

Toilet waters, after-shave lotions, perfumes, creams, soaps, bath orshower gels or deodorant or antiperspirant products, be they in the form6 of sticks or lotions, constitute examples of substances or finishedproducts in which the lactic ester of the invention contributes itsoriginal character.

They can also feature in shampoos and in hair products of any type.

They can also perfume talcs or powders of any nature.

They may also be suitable for ambient-air deodorants or any maintenanceproduct.

Another example of compositions into which the said compounds canadvantageously be introduced is represented by the customary detergentcompositions. These compositions generally contain one or more of thefollowing ingredients: anionic, cationic or amphoteric surfactants,bleaching agents, optical bluing agents, various fillers,anti-redeposition agents. The nature of these various components is notcritical and the lactic ester of the invention can be added to any typeof detergent composition. They can be introduced into textile softenersin liquid form or into compositions deposited on support, most often anon-woven fabric, intended for use in tumble dryers.

The level of lactic ester of the invention in the compositions accordingto the invention, expressed as a percentage by weight in the compositionin question, depends on the nature of the said composition (base forperfume or toilet water for example) and on the power and the nature ofthe sought effect in the final product. It goes without saying that in abase for perfume the level of lactic ester of the invention can varywidely, for example more than 5% by weight and can reach 90% by weightwhereas in a perfume, a toilet water or an after-shave lotion this levelcan be well below 50% by weight.

The level of lactic ester in detergent compositions, in particulardomestic, or in soaps, can be of the order of 0.01 to 2%.

They may also be included in perfumed shampoos at the rate of 0.005 to2% or to perfume any hair product.

Thus the lower limit of the level of lactic ester of the invention canbe that which causes a perceptible change in the smell of the fragranceor in the character of the finished product. In some cases, this minimumlevel may be of the order of 0.001% by weight. Obviously, levels can beused which are not contained in the limits mentioned above withoutthereby exceeding the scope of the present invention.

The products of the invention are particularly advantageous because oftheir olfactory stability during their application.

Embodiments of the invention are given below.

EXAMPLE 1

156.34 g (1.5 mol) of (R)-methyl lactate, 78.62 g (0.5 mol) ofcitronellol and 0.6 g of butyl titanate are placed in a flask.

The reaction mixture is heated to 90° C. for 24 h under a nitrogencurrent and under reduced pressure (140 mbar) and the liberated methanolis drawn off.

The reaction medium is washed in 3×100 ml of a 10% by weight NaClsolution.

The organic phase is dried with magnesium sulphate.

The organic phase is distilled under reduced pressure (0.2 mbar) and65.7 g of (R)-citronellyl lactate are collected between 115° C. and 118°C.

The (R)-citronellyl lactate is identified by NMR¹H and NMR¹³C whichshows the presence of two diastereoisomers (dia A and B) namely (R,R)and (R,S).

NMR¹H=(300.13 MHz; CDCl₃): 0.84 (d, J=6.5 Hz, 3H); 1.12 (m, 1H); 1.24(m, 1H); 1.32 (d, J=6.8 Hz, 3H); 1.42 (m, 1H+1H); 1.51 (s, 3H); 1.59 (s,3H); 1.63 (m, 1H); 1.90 (m, 2H); 2.87 (broad peak, 1H); 4.14 (m, 1H+2H);4.99 (t, J=7.1 Hz).

NMR¹³C=(75.47 MHz; CDCl₃): 16.8, 19.3 (dia A); 19.4 (dia B); 20.3, 25.3,25.6, 29.3 (dia A); 29.5 (dia B); 35.3; 36.4 (dia A); 36.9 (dia B);64.1; 66.7; 124.4; 131.4; 175.7.

The smell of the (R)-citronellyl lactate has a flowery character of lilyof the valley type, warm and rich and more natural than rosy alcohols.

EXAMPLE 2

Example 1 is reproduced using the (S)-methyl lactate.

43.77 g of (S)-citronellyl lactate are recovered.

The smell of the (S)-citronellyl lactate has a flowery honeysucklecharacter closer to citronellol, which gives it a less natural effectthan the (R)-citronellyl lactate.

EXAMPLE 3

Example 1 is reproduced using methyl lactate.

50 g of citronellyl lactate are recovered.

The smell of the citronellyl lactate has a flowery character of lily ofthe valley-honeysuckle type, less powerful and less natural than the(R)-citronellyl lactate.

EXAMPLE 4

Example 1 is reproduced using the (R)-methyl lactate anddihydrocitronellol.

The smell of the (R)-dihydrocitronellyl lactate has a citronella-like,grassy and woody character.

The (R)-dihydrocitronellyl lactate is identified by NMR¹H, the spectrumof which constitutes FIG. 1.

EXAMPLE 5

Example 1 is reproduced using the (S)-methyl lactate anddihydrocitronellol.

The smell of the (S)-dihydrocitronellyl lactate has a rosy, woody andlemony type character.

The (S)-dihydrocitronellyl lactate is identified by NMR¹H, the spectrumof which constitutes FIG. 2.

EXAMPLE 6

1.5 g of a 33% by weight solution of (R)-citronellyl lactate inpolysorbate 20 (sorbitol ester) and fatty acids (lauric, stearic, oleic)ethoxylated by 20 E.O. are incorporated in 98.5 g of a shampoo base.

The shampoo has the following composition by weight:

sodium lauryl sulphate + ethoxylated sodium lauryl 30% sulphate +disodium cocoamphodiacetate + hexylene glycol (MIRACARE 2MCA S/E)cocamidopropylamine oxide and lichen extract 1% (ANTIPELLICULE USNATEAO) Indian cress extract (CAPUCINE HS) 1% preservative (GERMABEN II)0.2% citric acid pH 6.0 to 6.2 demineralized water 67.3% perfume 0.5%

The perfumed shampoo is stable in terms of colour and smell over aperiod of 3 months when it is stored at 50° C. sheltered from light andwhen it is stored at 20° C. in daylight.

EXAMPLE 7

1.5 g of a 33% by weight solution of (R)-citronellyl lactate inpolysorbate 20 are incorporated in 98.5 g of a shower gel base.

The shower gel has the following composition by weight:

ethoxylated sodium lauryl sulphate + sodium 37.30% cocoamphoacetate +MIPA cocamide (MIRACARE CS) HS wild camomile 2.00% hydroxypropylatedguar (JAGUAR C162) 0.30% preservative (GERMABEN II E) 0.20%demineralized water 59.7% citric acid pH 5.9 perfume 0.50%

The perfumed shower gel is stable in terms of colour and smell over aperiod of 3 months when it is stored at 50° C. sheltered from light andwhen it is stored at 20° C. in daylight.

EXAMPLE 8

0.3 g of a 33% by weight solution of (R)-citronellyl lactate inpolysorbate 20 are incorporated in 99.7 g of a hydrating gel base.

The hydrating gel has the following composition by weight:

hydroxypropylated guar (JAGUAR HP 105) 0.8% hydroxylated guar +tri(hydroxypropyl)ammonium 0.2% chloride (JAGUAR C162) oleth 20(RHODASURF ON 870) 0.05% allantoin 0.2% benzophenone 4 (UNIVUL MS 40)0.5% glycerol 0.25% PCA sodium (NALIDONE) 2.4% citric acid 2.0% sodiumhydroxide (10%) pH 8 DMDMH hydantoin (NIPA GUARD DMDMH) 0.3% perfume0.1% polysorbate 20 (TWEEN 20) 0.2% deionized water 93%

The perfumed hydrating gel is stable in terms of colour and smell over aperiod of 3 months when it is stored at 50° C. sheltered from light andwhen it is stored at 20° C. in daylight.

EXAMPLE 9

0.3 g of (R)-citronellyl lactate is incorporated in 99.7 g of ahydrating cream base.

The hydrating cream base is prepared by mixing the following two phaseshaving the following composition by weight:

Phase A capryl/capric triglyceride (DERMOL M5) 4% mineral oil (MARCOL82) 2% stearyl alcohol 3% isopropyl myristate (WICKENOL 111) 2% glycerylstearate + polyethylene glycol 100 (ARLACEL 165) 6% dimethicone (MIRASILDM 300) 4% Phase B deionized water 70.7% glycerol 8% preservative(GERMABEN II) 0.3%

The perfumed hydrating cream is stable in terms of colour and smell overa period of 3 months when it is stored at 50° C. sheltered from lightand when it is stored at 20° C. in daylight.

EXAMPLE 10

0.2 g of (R)-citronellyl lactate is incorporated in 99.8 g of detergentpowder.

The detergent powder has the following composition by weight:

linear sodium alkylbenzene sulphonate (LABS NANSA) 10% SOAP 5% C12ethoxylated alcohol, 70E (SINPERONIC A7) 2% sodium tripolyphosphate(RHODIAPHOS HPA 3.5) 25% sodium carbonate 10% sodium silicate R2 5%sodium sulphate % sodium carboxymethylcellulose 1% sodium perborate 15%TAED 5% diethylenetriamine penta(methylene phosphonic acid) 1% (DEQUEST2066) antifoaming agent (RHODORSIL 20448) 1% optical bluing agent(TINOPAL DMS) 0.2%

The perfumed detergent powder is stable in terms of colour and smellover a period of 3 months when it is stored at 50° C. sheltered fromlight and when it is stored at 20° C. in daylight.

EXAMPLE 11

A perfuming composition is prepared containing: methyl dihydrojasmonate 10 g phenylethyl alcohol  15 g indole in 10% solution in DEP 0.5 g ofsolution benzyl acetate 2.5 g MAYOL(1-hydroxymethyl-4-isopropylcyclohexane)   5 g4-(4-hydroxy-4-methylpentyl)-3-cyclohexene-1-carboxaldehyde 4.5 g(LYRAL) p-tert-butyl-methylhydrocinammaldehyde (LILIAL)   5 g(R)-citronellyl lactate 7.5 g

The use of (R)-citronellyl lactate permits the reconstitution of a lilyof the valley base, which procures a much more natural effect than thebase which does not contain any of it.

What is claimed is:
 1. Citronellyl or dihydrocitronellyl lactates offormula (I) or (I′):


2. Citronellyl or dihydrocitronellyl lactate, optically active asregards the carbon in a position of the CH₃ group and of the esterfunction, in (R) or (S) form, of formula (Ia) or (I′a):


3. A process for the preparation of citronellyl lactate ordihydrocitronellyl lactate of formulae (I) and (I′):

comprising the step of a): reacting citronellol or dihydrocitronelloland a lactic acid, its salts or esters of formula (II):

wherein: R′ represents a hydrogen atom, an alkali-metal atom, anammonium radical or a linear or branched alkyl radical having from 1 to4 carbon atoms.
 4. A process for the preparation of citronellyl lactateor dihydrocitronellyl lactate, optically active as regards the carbon ina position of the CH₃ group and of the ester function, of formulae (Ia)and (I′a):

comprising the step of a): reacting citronellol or dihydrocitronelloland a lactic acid, its salts or esters, optically active, of formula(IIa):

 wherein: R′ represents a hydrogen atom, an alkali-metal atom, anammonium radical or a linear or branched alkyl radical having from 1 to4 carbon atoms.
 5. A process according to claim 3, wherein the compoundof formula (II) is lactic acid, sodium lactate, potassium lactate,ormethyl or ethyl esters of lactic acid.
 6. A process according to claim4, wherein the compound of formula (II) is lactic acid, sodium lactate,potassium lactate or methyl or ethyl esters of lactic acid.
 7. A processaccording to claim 5, further comprising in step a) the presence of anorganic solvent which forms an azeotrope with water.
 8. A processaccording to claim 6, further comprising in step a) the presence of anorganic solvent which forms an azeotrope with water.
 9. A processaccording to claim 3, further comprising in step a) the reaction of thelactic acid or its salts with phosgene, diphosgene(trichloromethylchloroformate) or thionyl chloride in order to obtain,respectively, 5-methyl-1,3-dioxan-1,3-dione or propene-one-1sulphite-1,2 with which the citronellol or the dihydrocitronellol isreacted.
 10. A process according to claim 4, further comprising in stepa) the reaction of the lactic acid or its salts with phosgene,diphosgene (trichloromethylchloroformate) or thionyl chloride in orderto obtain, respectively, 5-methyl-1,3-dioxan-1,3-dione or propene-one-1sulphite-1,2 with which the citronellol or the dihydrocitronellol isreacted.
 11. A process according to claim 3, further comprising afterstep a): b) distilling the corresponding alcohol released bytransesterification.
 12. A process according to claim 4, furthercomprising after step a): b) distilling the corresponding alcoholreleased by transesterification.
 13. A process according to claim 5,wherein the compound of formula (II) is (R)-lactic acid.
 14. A processfor the preparation of perfuming compositions, perfumed substances orperfumed finished products comprising the step of adding an effectiveperfuming quantity of at least one citronellyl lactate ordihydrocitronellyl lactate of formula (I) or (I′):


15. A process for obtaining perfuming compositions, perfumed substancesor perfumed finished products, comprising the step of adding aneffective quantity of at least one citronellyl lactate ordihydrocitronellyl lactate, optically active as regards the carbon in aposition of the CH₃ group and of the ester function, of formula (Ia) or(I′a):


16. Perfuming compositions, perfumed products and substances comprising,as active principle having an influence on the smell, an effectivequantity of at least one citronellyl lactate or dihydrocitronellyllactate of formula (I) or (I′) as defined in claim
 2. 17. Perfumingcompositions, perfumed products and substances comprising, as activeprinciple having an influence on the smell, an effective quantity of atleast one citronellyl lactate or dihydrocitronellyl lactate, opticallyactive as regards the carbon in a position of the CH₃ group and of theester function, of formula (Ia) or (I′a) as defined in claim
 3. 18.Perfumed article according to claim 16, in the form of perfume, toiletwater, after-shave lotions, perfumes, soaps, bath gels, shower gels,deodorant products, antiperspirant products, shampoos, hair product,talcs, powders, ambient-air deodorants, maintenance product, detergentcompositions, or textile-softening compositions.
 19. Perfumed articleaccording to claim 17, in the form of perfume, toilet water, after-shavelotions, perfumes, soaps, bath gels, shower gels, deodorant products,antiperspirant products, shampoos, hair product, talcs, powders,ambient-air deodorants, maintenance product, detergent compositions, ortextile-softening compositions.
 20. A process according to claim 14,wherein the product of formula (I) gives a flowery character.
 21. Aprocess according to claim 15, wherein the optically active citronellyllactate (R) of formula (Ia) gives a flowery character of lily of thevalley.
 22. A process according to claim 15, wherein the opticallyactive citronellyl lactate (S) of formula (Ia) gives a floweryhoneysuckle character.
 23. A process according to claim 15, wherein theoptically active dihydrocitronellyl lactate (R) of formula (I′a) gives acitronella-like, grassy, woody character.
 24. A process according toclaim 15, wherein the optically active dihydrocitronellyl lactate (S) offormula (I′a) gives a rosy, woody, lemony character.